Hello. Here is a short guide on factorials.
Before going into the definition of factorials. Here are some examples of factorials.
As you can see, a factorial is a compact way of expressing the multiplication of descending (or ascending) positive whole numbers.
With factorials, the general case is:
There are also some special cases with and .
Division With Factorials
You may encounter fractions with factorials in the numerator and in the denominator. Here are some examples.